Over the past few decades, there has been interest in chalcogenide materials for use in semiconductor devices, such as solar cells, photodetectors, or electroconductive electrodes. One such chalcogenide material is copper telluride (CuTe), which has been investigated for use as a cell material in conductive bridge random access memory (conductive bridge RAM) and phase change random access memory (PCRAM). One of the current difficulties associated with CuTe is the deposition of this material. CuTe is conventionally formed by a physical vapor deposition (PVD) or chemical vapor deposition (CVD) process, or by codeposition of copper and tellurium onto a surface within an evacuated chamber. However, due to the equipment and targets needed, these techniques are expensive and take a considerable amount of time to become production worthy.
Atomic layer deposition (ALD) of chalcogenide materials, such as certain metal tellurides or certain metal selenides, has been investigated. Alkylsilyl tellurides and alkylsilyl selenides have been reacted with metal halides to form metal tellurides or metal selenides, such as SbTe (Sb2Te3), GeTe, GeSbTe, ZnTe, BiTe(Bi2Te3), ZnSe, BiSe(Bi2Se3), InSe(In2Se3), or CuSe (Cu2Se). Alkylsilyl selenides, such as bis(triethylsilyl) selenide, have also been reacted with copper(II) pivalate to form CuSe, Cu2-xSe, and Cu2Se. However, ALD processes for forming chalcogenide materials are limited by the availability, reactivity, and toxicity of appropriate ALD precursors.
It would be desirable to form additional chalcogenide materials, such as CuTe, by ALD processes.